#include <stdio.h>
#include <stdlib.h>

typedef char        ElementType;
typedef struct TNode*Position;
typedef Position    BinTree;
struct TNode
{
    ElementType Data;
    BinTree     Left;
    BinTree     Right;
};

BinTree CreatBinTree(){return NULL;} /* 实现细节忽略 */
void PreorderPrintLeaves(BinTree BT);

int main()
{
    BinTree BT=CreatBinTree();
    printf("Leaf nodes are:");
    PreorderPrintLeaves(BT);
    printf("\n");
    
    return 0;
}

/* 你的代码将被嵌在这里 */
void print(BinTree BT)
{
    printf(" %c",BT->Data);
}

void PreorderPrintLeaves(BinTree BT)
{
    if(BT)
        if(BT->Left||BT->Right)
        {
            PreorderPrintLeaves(BT->Left);
            PreorderPrintLeaves(BT->Right);
        }
        else
            print(BT);
}